package com.jiermt.M060302;

public class ExceptionDemo1 {
    public static void main(String[] args) {

       show();

    }
    public static void show(){
        int[] arr = {1,2,3};
       /* System.out.println(arr[3]);*/
        String str  = null;
        System.out.println(str);
       System.out.println(str.length()); //空指针异常
    }
}
